Enhanced gettering of gold at end-of-range defects in high energy ion implanted silicon

Abstract

We report on the gettering behavior of Au at end-of-range (EOR) defects in float-zone grown Si(111), implanted with 1.5 MeV Au 2+ ions at room temperature. The effects of implantation dose and annealing temperature on the thermal evolution of gettering behavior of EOR defects have been investigated using Rutherford backscattering spectrometry, while the microstructural evolution of Au implanted Si(111) has been studied using cross-sectional transmission electron microscopy combined with high resolution transmission electron microscopy. The gettering efficiency of EOR defects, comprising of dislocation loops, has been found to increase with increase in implantation dose up to 1.2 x 10 15 ions cm -2 , beyond which it was found to saturate at about 5 x 10 14 atoms cm -2 for annealing at 850 o C. We have observed that the gettering efficiency of the EOR defects for Au increased with increase in annealing temperature and reached 9 x 10 14 atoms cm -2 for annealing at 950 o C. The observed enhanced gettering efficiency of EOR defects is very promising for gettering applications in Si devices.